For all of their power, dungeons are surprisingly fragile creatures. Their most obvious weakness is their cores, which are always accessible and on full display on the dungeons lowest floor. It is not known why dungeons always leave their cores vulnerable in this way. The cores are highly delicate and can be shattered by a physical attack of relatively little strength, or if one wants to take advantage of the high market value of an intact core, it can be picked up and removed from the dungeon. For a dungeon of such depth and power that reaching the core is infeasible, a team of mages can simply set up a barrier above the dungeon to prevent the ingress of mana. Whatever the method, the result is the same slow withering; ambient mana inside the dungeon drops, traps cease to reset for the purely mechanical or fail completely for those that are mana driven, and the monsters begin to starve. Mana leaks out from the dungeon stone, reducing its strength, eventually leading to structural collapse within two to three months.

- Excerpt from Everything you've never wanted to know about dungeons.

The dungeon hurt. It was blind to all except the immediate vicinity of its core, and its thoughts felt like they were fighting their way through treacle. Adding a new floor had obviously gone horribly wrong, and the dungeon had effectively ejected its own core from the labyrinth that made up its body. First thing first, the dungeon knew it absolutely must not lose consciousness, or it would never wake up again. It started pulling as much mana as its limited reach permitted towards the core, pushing back against the fugue that sought to claim it.

The dungeon pondered its options. It needed to either relocate its core back to the fifth floor, or else get this new floor successfully registered. It also needed to do so quickly, and while manually feeding mana into the core. It had been told that the reason this floor could not be added successfully was due to the fifth floor not cycling enough mana. What did cycling mana mean? What was different about the fifth floor? The first thing that came to mind was that the dungeon had left its fifth floor unpopulated, except for the single emperor slime. After all, any new fifth floor monsters required more than its 20 mana cap to summon, and it didn't want to risk further core reinforcement. How ironic it would be if its playing safe resulted in its death...

The monsters certainly ate mana, but did that count as cycling it? Surely a bunch of monsters eating up mana should reduce the mana available for subsequent floors? In any case, in its current state the dungeon was unable to spawn monsters on any floor, so it was unable to test this theory. Then what of its other option? How could it get its core back into the fifth floor core room. The hole connecting the fifth and sixth floor core rooms was still in place, but the dungeon no longer had gravity on its side. With its mana scarcity, it wasn't able to push a pillar of stone back up. Since it had lost communication with its monsters, it couldn't call one to carry it back either. Handicapped as it was, the dungeon was completely unable to find a way to reattach its core to its body.

It occurred to the dungeon that this was not actually the first time it had been in such a state; it hadn't had any floors when it was born after all. It hadn't been doing much in the way of thinking back then, and had constructed a first floor on pure instinct. If the core had since evolved to operate under higher mana density, then maybe that was why it was struggling now but was able to function without issue back then. If it treated its old body as a passageway to the surface, then it would not be in violation of the Rules if it set up a new first floor here. Operating on pure instinct as it was back then, the dungeon had little in the way of memory of how creating the first floor went, but right now it couldn't think of any better options.

The dungeon pushed mana into the surrounding stone, stealing it from its previous body, and transforming it from the sixth floor of a withering dungeon to the first floor of a new one. The dungeon felt its perception expand around the room, and pleased with the success, pushed out into the surrounding rooms. As it pushed mana out from the core room, the dungeon very nearly blacked out once more. Dangerous! It needed mana for the core to continue operation, but it also needed it to expand. But it had a few rooms now, and that would have to do. Now came another problem; if monsters truly were a vital part of a floor, it would need to summon some, but in its current condition that risked disaster. The dungeon waited, pulling mana into its core as forcibly as it was able, and found that its mana stabilized at 3/20. Barely enough for basic monster summoning, but enough nevertheless. The dungeon braced itself, and summoned a slime.

That was... actually not as bad as it expected. Yes, it was hit with a wave of tiredness, but not to the point of almost blacking out. That was comforting. Then time to rinse and repeat. The dungeon again waited as it pulled in mana then summoned the next slime. After the fourth slime, the dungeon noticed something surprising; it could now reach 4 mana before the drain matched the regeneration. So monsters did indeed help circulate mana in some way? That was useful information, so once it had fully populated the rooms it had already taken over, it proceeded to take over the rest of the floor, summoning more monsters all the while. With a few weeks of effort it was able to reach 7 mana, but still needed to consciously pull mana towards its core to get a viable mana density. But at that point:

Error: Unable to summon monster due to invader present on floor

What?! Seriously? Now of all times? Luckily claiming the new core room had sealed over the hole, or the invader may have dropped right onto its core. The dungeon shifted its perception to the staircase, and what it saw looked very much like an emperor slime. But... How? The slime did not belong to the dungeon. Could the dungeon still view information about it regardless? "Show me information on the invader."

Unnamed emperor slime

HP: 20/50

mana: 0/10

Active status effects: starving

It was starving? This floor had nowhere near the mana density it would require, but it was already half dead. It hadn't been here long enough for that, and the floor above did have plenty of mana. Or did it? The dungeon pondered what was happening up above now that the core had been detached. Did the whole dungeon lose its mana? Were all of its monsters starving to death up there? Then this slime was really its old slime from the fifth floor? The dungeon felt... guilty. Another new emotion; it seemed to be building up a few of them since its expansion. Also an illogical one; the monsters weren't sentient, had no free will, and were literally born to die. What reason did the dungeon have to feel guilty over their fate? In any case, this invader was heading for its core, presumably to try and feed off the higher mana there. That couldn't be permitted. The dungeon ordered its new set of slimes to gather and attack.

As powerful as the emperor slime was compared to its unevolved counterparts, it was starved half to death, and could do nothing against the whole floor moving against it in concert.

Invader killed. As invader did not possess a soul, no dungeon points are awarded.

That answered an earlier question; it could never gain dungeon points from its own monsters because they lacked a soul of their own. Even after being completely detached from the dungeon nothing had changed. That could be problematic for the future; the end goal of the dungeon was to summon intelligent monsters with their own free will, but how could that be accomplished if the dungeon could not create souls? Luckily that was not a problem that affected the current situation. The dungeon noticed that having the monsters grouped together like this harmed the mana increasing effect, so sent them back to their rooms, and continued summoning.

A few days more were enough for it to complete the floor, and increase its mana cap to 8. Now what should it do next? The mana density was still insufficient for the core to operate normally, so further expansion was required urgently. Should it dig down, or try and reclaim the floors above? Reclaiming would take less mana, and would obviate the need to move the core around, which after the previous experience the dungeon really didn't want to do, so the dungeon sent its mana up the staircase, and started reclaiming its old deserted fifth floor. Watching the flows of mana as its perception expanded, the dungeon saw the density on the fifth floor had dropped massively, and was in fact lower than that of the new floor. The dungeon sent up some of the new slimes, and watched the mana density increase. The way monsters interacted with mana was certainly weird...

In the end, the dungeon sent up all of the slimes from the new floor, and created big slimes to replace them. It would have to repeat this for each new floor it reclaimed, given that it was expanding in the wrong direction. But at least the plan was working; it was now up to 12 max mana, and while it still had to manually shift mana to the core room it was definitely having an easier time of it. With the full floor reclaimed, the dungeon wondered why it hadn't had a notification about the new floor. "Show me my information."

Unnamed slime dungeon [Errant], [Withering]

Floors:

Mana: 12/#!$& (regeneration ?/second)

Dungeon Points: 0

Well, that was more than a little disturbing... It obviously couldn't rely on the messenger right now, so the dungeon decided to assume the takeover of the fifth floor was complete and move onto the fourth. Now it had two floors of monsters that needed to be shuffled up, and giant slimes to summon on the bottom level. Nothing unexpected happened, and the dungeon watched happily as the ambient mana continued to climb. That left it with a 15 mana cap, and a problem. For the next floor it should be summoning king slimes, but it couldn't gather sufficient mana for the summoning. How well would a lesser monster work? The dungeon reclaimed the third floor, shifted monsters up and continued summoning giant slimes. Its mana cap barely increased to 16. It did appear that the lower level monsters were not as helpful as could be. But this was the reason the dungeon was exclusively using slimes for these summons. It ordered the bottom floor slimes to merge into king slimes, and found the ambient mana jumped up again, bringing its mana break even point to 18.

At this point mana density was sufficient that the dungeon could even survive without manually pushing mana around, although manual intervention did still allow it to store more mana before the leaks outweighed the regeneration. This was fortunate because with no warning the dungeon shook, and it suddenly found itself utterly unable to concentrate on anything other than the fact that it was in violation of the Rules. It knew that it no longer had a viable route to the surface. In blind panic, the dungeon began reclamation of the second floor, and without taking time to place monsters, moved on to the first. In places, the first floor had a different feeling, more like when the dungeon was spreading on the surface than reclaiming the lower floors. In these places the ceiling was displaying obvious cracks. The problem became apparent as the dungeons influence had almost reached the entrance; a room had collapsed, separating the entrance from the rest of the labyrinth. The dungeon dug it out as fast as its mana permitted, and reclaimed back as far as the entrance. The sense of urgency dropped away as quickly as it had come.

Taking a moment to consider what had just happened, the dungeon realised it had broken the Rules and nothing bad had happened... Sure, it was suddenly overwhelmed with the urge to rectify things, but there wasn't actually any punishment. It hadn't deliberately broken the Rule itself, but it could hardly blame it on anyone else, what with the complete lack of anyone else in existence. Were accidents ok? Or were the Rules just a set of particularly heavy instincts? It also needed to consider the way it knew what the problem was despite it being two floors out of sight, even if it didn't have any idea where the problem was until it came across the collapsed room. This was definitely food for thought, even if not a reason to change its behaviour right now.

Taking over the last two floors without doing anything with monsters hadn't done anything for the mana density, so the dungeon shuffled everything up one floor again and started the slow process of merging into emperor slimes. With that done, the mana density had finally recovered to above where it was before this mishap had begun, and the core was finally functioning normally once more, albeit still with the odd crystalline growths and accompanying dull itch. But there was still one floor to go, so another shuffle, and another set of emperor slime merges. With its full mana cap of 20 back, along with the ability to directly summon king slimes, it went a bit faster this time. But it knew it should have something more powerful than an emperor slime on its new sixth floor, so it would need to merge further.

New monster unlocked:

And here we go again...